Feb 10 2020

Vicidial: There is a time synchronization problem with your system, please tell your system administrator

There is a time synchronization problem with your system, please tell your system administrator

In case you have this error upon installation or upgrade your Vicibox/Vicidial check the following:

  1. Using timedatectl utility make sure server’s timezone is set correctly and server’s date/time is correct. Set proper timezone if needed. Get  a list of timezones:

For the specific location you can use:

And set the proper one:

2. Check that timezone is correct in /etc/php7/apache2/php.ini. Set proper timezone if needed and restart Apache.

3. If it did not help check and compare time values in Vicidial database, server time and PHP time. Use the following command:

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Feb 10 2020

Vicidial error: Code Expects Different Schema

Vicidial-warning-code-expects-different-schemaAfter database dump restoration taken from older Vicibox to the latest Vicibox 9.0.1 I got the following error in Admin -> System Settings section:

WARNING: Code expects different schema: 1585

It’s not possible to change or save any setting. The reason is obvious: Vicibox 9 has new and altered tables and functions so you will have to add them to the restored database before you can use system. Continue reading

Feb 07 2020

FlexiSip installation and configuration on CentOS 7

Flexisip

Flexisip is a complete, modular and scalable SIP server suite written in C++11, comprising proxy, presence and group chat functions.

Flexisip offers an easy-to-install SIP server solution, offering all the features required to deploy your own SIP service tuned for mobile or desktop applications, “out of the box”.

Flexisip can be integrated into your SIP infrastructure for various purposes : Continue reading

Feb 06 2020

Varnish error Backend fetch failed

Here are some generic tips on finding the actual cause of “Backend Fetch Failed” error shown by Varnish Cache. Continue reading

Feb 06 2020

Managing of Varnish backends

This article explains how you can manage Varnish backends from command line, check varnish backend health status and mark backends as healthy or sick without restarting or reloading Varnish. Continue reading

Feb 06 2020

Varnish Backend fetch failed Too many headers

This article describes particular case of Varnish error Backend fetch failed Too many headers. This error happens when there are too many headers being sent to backend server. Here is how you can troubleshoot and fix this error. Continue reading

Feb 02 2020

FlexiSip installation and configuration on Debian 9

Flexisip

Flexisip is a complete, modular and scalable SIP server suite written in C++11, comprising proxy, presence and group chat functions.

Flexisip offers an easy-to-install SIP server solution, offering all the features required to deploy your own SIP service tuned for mobile or desktop applications, “out of the box”.

Flexisip can be integrated into your SIP infrastructure for various purposes : Continue reading

Feb 02 2020

Flexisip error Failed to find shared library for backend mysql

FlexisipI installed Flexisip using official documentation , installed additional components like MariaDB (MySQL) and Redis, performed initial setup of configuration files, created database and DB user.

I started flexisip services with

and by looking in /var/opt/belledonne-communications/log/flexisip/flexisip-conference.log I noticed the following error:

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Jan 24 2020

Magento server performance configuration

magento-server-perofrmance-setupThere are best practices in Magento 2 performance configuration of operating system, MySQL, PHP and webserver. This article covers important configurations of all components that will speed up the Magento site.

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Jan 24 2020

DDoS Protection With IPtables

iptablesThere are different ways of building your own anti-DDoS rules for iptables. This guide will describe comprehensive approach to protect server from DDoS attacks:

  1. Select the best iptables table and chain to stop DDoS attacks
  2. Tweak your kernel settings to mitigate the effects of DDoS attacks
  3. Use iptables to block most TCP-based DDoS attacks
  4. Use iptables SYNPROXY to block SYN floods

Here we’ll only cover protection from TCP-based attacks. Most UDP-based attacks are amplified reflection attacks that will exhaust the network interface card of any common server. Continue reading

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